Open flap detector for filled cartons

ABSTRACT

Pivotal feelers are disposed above and below the cartons as they are transferred in succession from a flap sealing zone to a palletizing zone to trip a switch adapted to stop the transfer in the event one of the top flaps on a carton comes loose and engages the upper feeler or in the event the bottom sags or a bottom flap drops into engagement with the lower feeler. The feelers are mechanically connected to a cam or abutment trip for a switch in the control circuit of a drive motor for the conveyor transferring the cartons from one zone to the other.

United States Patent 91 Pagdin et al.

[ 1 OPEN FLAP DETECTOR FOR FILLED CARTONS [75] Inventors: William G. Pagdin, Milwaukee; Robert F. Risley, Wauwatosa, both of Wis. v

[73] Assignee: Jos. Schlitz Brewing Company, Milwaukee, Wis.

[22] Filed: Jan. 4, 1971 [21] Appl. No.1 103,474

[52] U.S. Cl. ..53/78, 53/53, 209/80,

209/90 [51 Int. Cl. ..B65b 57/04 [58] Field of Search ..53/78, 53; 209/80, 90; 73/52 [56] References Cited UNITED STATES PATENTS 5/1970 Colaw ..209/90X 2/1952 Kall 53/78X [451 Feb. 6, 1973 Primary Examiner-Travis S. McGehee Alt0rney-Andrus, Sceales, Starke & Sawall [57] ABSTRACT Pivotal feelers are disposed above and below the cartons as they are transferred in succession from a flap sealing zone to a palletizing zone to trip a switch adapted to stop the transfer in the event one of the top flaps on a carton comes loose and engages the upper feeler or in the event the bottom sags or a bottom flap drops into engagement with the lower feeler.

The feelers are mechanically connected to a cam or abutment trip for a switch in the control circuit of a drive motor for the conveyor transferring the cartons from one zone to the other.

10 Claims, 4 Drawing Figures PATENTED FEB 6 I973 sum 1 or INVENTORS ILLIAM G.PAGD|N BERT F. RISLEY PATENTEDFEB s 1975 SHEET 2 OF 3 INVENTORS WILLIAM G.PAGDIN ROBERT F. RISLEY PATENTEU FEB 6 i975 3,714,759

SHEET 3 OF 3 INVENTORS WILLIAM G.PAGDIN ROBERT F. RISLEY OPEN FLAP DETECTOR FOR FILLED CARTONS BACKGROUND OF THE INVENTION wardly from the plane of the top of the carton and may lie in any position within the range of from a slight upward tilt to a wide open position where it maybe depending outwardly from the upper side edge of the carton. In the case of a lower flap the positioning generally varies angularly from the plane of the bottom of the I carton.

Where the carton is packed with bottles or cans of liquid material, in the event a bottle breaks or a can leaks the bottom of a carton will become wet and sag downwardly from the plane of the bottom. It is desirable to also detect this fact.

Heretofore photo-electric devices have been employed to detect the conditions described. However, it has been generally difficult to install properly sensitive equipment of this type, and the difficulties and cost of maintaining it in operative condition have been considerable.

For instance the conveyor for transferring the cartons generally requires two separate laterally spaced tracks or belts supporting the cartons at their outer edges leaving the intermediate portions of the bottom of the cartons free to sag if wet, and leaving the bottom flaps at least somewhat free to droop if loose. The belts employed must be of substantial vertical thickness in order to sustain the loaded cartons.

With such a conveyor structure it is difficult to provide a lateral photo-electric beam close enough to the plane of the bottom to detect the undesirable conditions of a carton in many instances.

Another instance of difficulty applies to the conditions described for detection of loose upper flaps since in some cases a loose flap may in fact hang downwardly from the upper side edge of the carton and not interfere with a photoelectric beam directed across the top of the carton.

SUMMARY OF THE INVENTION The present invention mechanically detects the undesirable conditions of the carton both on the top and the bottom and mechanically trips a switch in the control circuit for the conveyor.

In carrying out the invention a pivotally mounted feeler extends closely across the top of the carton and down along each side thereof to be engaged by a loose flap disposed in any of the angular positions described, but to allow a carton with the top flaps properly sealed to pass beneath without engagement therewith.

Similarly a pivotally mounted feeler extends transversely close to the bottom of the carton between the two conveyor belts to be engaged by any sagging of a wet or loose flap, but to allow a carton with the bottom flaps properly sealed and free from sagging to pass over the feeler without engagement therewith.

The feelers may comprise generally upper and lower vertically disposed plates extending in planes transverse to the path of the cartons and secured to corresponding parallel pivotal shafts connected at one end thereof by a link joining crank arms secured to the shafts. The other end of one of the shafts may carry a cam or abutment adapted to engage a limit switch when rotated by swinging of either of the detection plates from its vertical position.

The upper detection plate hangs from its pivotal shaft and carries a transverse rod near its lower edge with the outer ends of the rod bent downwardly adjacent the opposite sides of the cartons to be engaged by a wide open flap as previously explained.

The lower detection plate extends upwardly from its pivotal shaft to dispose its upper edge close to the bottom of the cartons to detect any evidence of sagging.

The weight of the upper plate is substantially greater than that of the lower plate to thereby maintain the latter in its upright position as cartons pass therebetween.

In order to provide the desired counter balancing between the upper and lower pivotal shafts the upper plate is secured to and depends from one side of the upper shaft and the lower plate is secured to and extends upwardly from the same side of the lower shaft, and the crank arms joined by the connecting link extend in opposite directions from their corresponding shaftsso that the link generally is bisected by the plane containing the axes of the shafts.

The limit switch is in the control circuit of the conveyor drive motor and preferably stops the motor and conveyor upon detection of a defective carton.

The conveyor generally comprises a pair of V-belts spaced laterally to engage and support each successive carton along its opposite side edges. The belts are mounted on end pulleys and are driven by the pulleys at one end to effect movement of the cartons successively through the detection zone between the detector plates. The drive pulleys for the belts are mounted upon a driven shaft having a sprocket at one end connected by a chain to the drive motor.

The pulleys at the opposite ends of the belts from the drive pulleys are individually mounted for free rotation and for belt tightening adjustment in line with the corresponding drive pulleys.

A fixed track is disposed to support each belt in its upper flight in the detection zone so as to maintain the cartons at the desired height as they pass beneaththe upper plate and above the lower plate.

Suitable stops may be provided to limit the pivotal movement of the shafts as by engagement with the lower detection plate as the same'swings in either' direction.

BRIEF DESCRIPTION OF THE DRAWING- DESCRlPTlON OF THE PREFERRED EMBODIMENT The preferred embodiment of the invention is illustrated in the drawings and comprises a conveyor system 1 and a flap detection mechanism 2.

The conveyor mechanism 1 comprises a pair of laterally spaced parallel endless V-belts 3 disposed to receive filled cartons 4 from a carton sealing zone or mechanism 5 and to transfer the same successively to a palletizing zone or mechanism 6.

The V-Belts 3 are carried by individual drive sheaves 7 at one end and individual idler sheaves 8 at the other end thereof and are spaced to engage the opposite longitudinal side edges of the cartons 4 to support the latter.

The drive sheaves 7 are secured upon a transverse drive shaft 9 carried by suitable end bearings 10 mounted on the horizontal flanges of corresponding frame side rails 11.

The idler sheaves 8 are rotatably mounted on separate stub shafts 12 secured to the vertical flanges of the corresponding side rails l 1. g

The side rails 11 are supported upon vertically adjustable posts 13 adjacent each end of the conveyor.

The drive shaft 9 carries a sprocket 14 at one end and which receives a chain 15 from a suitable drive motor 16 disposed beneath the conveyor for driving the V-belts 3.

Each stub shaft 12 has a threaded shouldered end 17 extending through a horizontal slot 18 in the vertical flange of the corresponding side rail 11 and is secured at an adjusted position in the slot for adjustment of belt tightness by nut 19 threadedupon the end 17.

The vertical flange of each side rail 11 has a side flange 20 secured thereto beneath the upper flight of the corresponding V-belt 3 to support the same against downward sagging of the belt under the weight of cartons 4.

The flap detection mechanism 2 comprises in general interconnected pivotally mounted feelers 21 and 22 respectively above and below the path of transfer of cartons and a control mechanism 23 actuated thereby.

The upper feeler 21 comprises a vertical detector plate 24 secured at its upper end by bolts 25 to a flat side of a shaft 26. I

A vertical slot in plate 24 for receiving each bolt 25 provides for vertical adjustment of plate 24 to accommodate different height cartons 4.

The shaft 26 has cylindrical ends joumalled in bearings-28 at the upper end of support posts 29.

The posts 29 extend upwardly frombrackets 30 secured to 'th'evertical flangesof the corresponding side rails l 1 on opposite sides of conveyor 1.

The detector plate 24 extends transversely of conveyor 1 for nearly the distance between V-belts 3 and has a transverse rod or bar 31 secured to one side thereof near its lower edge. v

The bar 31 has its ends turned downwardly to provide depending side arms extending close to the sides of the carton 4 as the latter pass therebetween.

The upper feeler 21 is thus constructed to detect unglued top flaps on carton 4 in any of the positions 32, 33' and 34 illustrated in broken lines in FIG. 3, and in any intermediate position.

A flap in any 'of the positions described will engage the upper fe'eler 21 and swing it in the direction of movement of the carton along conveyor 1, thereby rotating shaft 26 to actuate the control mechanism 23 as will be described later.

The lower feeler 22 comprises a vertical detector plate 35 extending transversely beneath the path of carton 4 with its upper edge close to the bottom of the carton.

The lower edge-of plate 35 is secured by bolts 36 to the flat s ide of a shaft 37 which has cylindrical ends joumalled in the corresponding brackets 30 on opposite sides of conveyor 1.

The lower feeler 22 is constructed and disposed to detect either a loose flap extending downwardly from the carton or a sagging bottom, which latter indicates wetting of the carton bottom as by breaking or leakage of a container within the carton.

For this purpose an angularly depending flap or a sagging bottom will engage the upper edge of detector plate 35 and swing the latter in the direction of movement of the carton along conveyor 1, thereby rotating shaft 37 to actuate the control mechanism 23 as will be described later.

Both shafts 26 and 37 are connected to rotate simultaneously in opposite directions so that swinging of either detector plate 24 or detector plate 35 in the direction of carton travel will cause the other plate to swing in the same direction.

For this purpose a connecting rod 38 is pivoted at its upper end to a crank arm 39 secured on the end of shaft 26' and extending horizontally therefrom in the direction of carton travel, and is pivoted at its lower end to a crank arm 40 secured on the end of shaft 37 and extending horizontally therefrom in a direction opposite that of carton travel. By this construction swinging of detector plate 24 in the direction of carton travel effecting clockwise rotation of shaft 26 as viewed in FIG 1, will effect counter-clockwise rotation of shaft 37. Likewise, swinging of detector plate 35 in the direction of carton travel will effect counter-clockwise rotation of shaft 37.

Detector plate 24 is secured to the left side of shaft 26 as viewed in FIG. 1 so that as the plate swings in the direction of carton 'movement the lower edge of the plate tends to rise and clear the obstacle causing the swinging. Likewise, detector plate 35 is secured to the left side of shaft 37 as viewed in FIG; 1 so that as the plate swings in the direction of carton movement the upper edge of the plate'tends to lower and clear the obstacle causing the swinging.

The upperdetector plate 24. of feeler 21 hangs downwardly from shaft 26 and tends to keep the lower detector plate 35 in an upright position by reason of the factthat plate 24 and bar 31 are heavier than plate 35.

Upon rotation of shaft 37 caused by'the swinging of either detector plate 24 or 35 by a carton the conveyor 1 is stopped as by stopping the drive motor 16.

For this purpose a normally closed limit switch 41 is connected in the control circuit for motor 16 as shown in FIG 4.

The switch 41 is mounted on one of the posts 29 and is actuated by a pivotal arm 42 having a roller 43 at its outer end.

The roller 43 serves as a cam follower riding upon the edge of cam disc 44 secured to one end of shaft 37.

Disc 44 has riser 45 thereon in the form of a screw and which lifts roller 43 and arm 42 when shaft 37 rotates in response to a defect in a carton 4.

Pivotal rising of arm 42 opens the control circuit and denergizes relay 46 in the motor circuit, thereby opening it to stop the motor.

The relay 46 has a holding circuit 47 for preventing re-energization and closing of the relay upon return of the detector feelers to vertical position, until a manually operable button switch 48 in the holding circuit permits re-energization of the relay.

Stopping the conveyor 1 upon detection of a defect in a carton moving thereon serves as a signal to an operator and enables correction of the defect or removal of the defective carton from the line.

The apparatus thus provided serves to detect an abnormal projection from a carton and to signal the operator by stopping the transfer of the carton.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

lclaim:

1. In combination with a conveyor, an open flap detector for. filled cartons moving along-the conveyor, comprising pivotal feeler means disposed adjacent the path of the cartons to be engaged by an open or displaced flap of a carton in any position of the flap other than closed, said feeler means including a generally L- shaped feeler having a generally horizontal leg located transversely above the conveyor and disposed to be engaged by an upwardly displaced flap of a carton, said feeler also including a generally vertical leg extending downwardly from the horizontal leg and disposed to be engaged by a laterally displaced flap of a carton, and signal means actuated by said feeler in response to an open or displaced flap condition.

2. In combination with a conveyor, an open flap and sagging bottom detector for cartons moving along a conveyor, comprising first pivotal feeler means disposed adjacent the path of the carton to be engaged by an open or displaced flap of a carton, said first pivotal feeler means disposed above the cartons as they move along a conveyor and comprising a first feeler depending from a first pivotal shaft with the lower edge portion of the first feeler disposed adjacent to and transversely of thecartons as they move along the conveyor, said first feeler also including arms extending downwardly from said feeler adjacent the sides of the cartons as they pass beneath said feeler, second pivotal feeler means disposed beneath the cartons as they move along the conveyor and comprising a second feeler extending upwardly from a second pivotal shaft with the upper edge of the second feeler disposed adjacent to and transversely of the cartons, said conveyor exposing the major portion of the bottoms of the cartons for detection of sagging thereof, and signal means operably connected to said first and second feeler means and disposed to be actuated by either feeler means to signal a displaced flap or a sagging bottom of a carton.

3. The construction of claim 2 and means inter-connecting said pivotal shafts to effect counter-weighting of said lower upstanding plate by said upper depending 31? In combination with a conveyor, a detector for cartons moving along a conveyor, comprising pivotal feeler means disposed adjacent the path of the cartons to be engaged by an abnormal projection of a carton, said pivotal feeler means disposed beneath the cartons as they move along the conveyor and comprising a feeler extending upwardly from a pivotal shaft with the upper edge of the feeler disposed adjacent to and transversely of the cartons, said conveyor exposing the major portion of the bottoms of the cartons for detection of sagging thereof, and signal means actuated by said feeler to signal sagging of the bottoms of the cartons.

5. The construction of claim 4 in which said means comprises a drive motor for the conveyor, a control circuit for said motor, a switch in said signal control circuit, and cam means on said pivotal shaft actuating said switch in response to pivotal turning of said shaft by said feeler.

6. The construction of claim 3, and means interconnecting said pivotal shafts to operate in unison, and said signal means is actuated by pivotal movement of one of said shafts.

7. The construction of claim 6 in which said signal means comprises a drive motor for the conveyor, a control circuit for said motor, a switch in said control circuit, and cam means on one of said pivotal shafts to actuate said switch in response to pivotal turning of said shafts be either of said feelers.

8. The construction of claim 6 in which the conveyor comprises a pair of parallel horizontally spaced side rails, a sheave rotatably carried at each end of each side rail with the sheaves at one end mounted upon a transverse drive shaft carried by the side rails, an endless V- belt mounted on the sheaves for each side rail and providing an upper flight in which the belts engage beneath the opposite side edge portions of the cartons being transported thereon leaving the central portions of the cartons exposed and unsupported, and bracket means carried by each side rail and mounting said first and second pivotal shafts.

9. The construction of claim 8 in which said signal means comprises a drive motor for the conveyor, a control circuit for said motor, a switch in said control circuit, and means on one of said pivotal shafts to actuate said switch and stop said motor in response to pivotal turning of said shaft by either of said feelers.

10. The construction of claim 8 and means on each side rail extending immediately beneath and parallel to the upper flight of the corresponding V-belt to prevent sagging ofthe latter from the weight of cartons being transferred, to thereby provide clearance between a non-sagging properly sealed carton bottom and the second feeler. 

1. In combination with a conveyor, an open flap detector for filled cartons moving along the conveyor, comprising pivotal feeler means disposed adjacent the path of the cartons to be engaged by an open or displaced flap of a carton in any position of the flap other than closed, said feeler means including a generally L-shaped feeler having a generally horizontal leg located transversely above the conveyor and disposed to be engaged by an upwardly displaced flap of a carton, said feeler also including a generally vertical leg extending downwardly from the horizontal leg and disposed to be engaged by a laterally displaced flap of a carton, and signal means actuated by said feeler in response to an open or displaced flap condition.
 1. In combination with a conveyor, an open flap detector for filled cartons moving along the conveyor, comprising pivotal feeler means disposed adjacent the path of the cartons to be engaged by an open or displaced flap of a carton in any position of the flap other than closed, said feeler means including a generally L-shaped feeler having a generally horizontal leg located transversely above the conveyor and disposed to be engaged by an upwardly displaced flap of a carton, said feeler also including a generally vertical leg extending downwardly from the horizontal leg and disposed to be engaged by a laterally displaced flap of a carton, and signal means actuated by said feeler in response to an open or displaced flap condition.
 2. In combination with a conveyor, an open flap and sagging bottom detector for cartons moving along a conveyor, comprising first pivotal feeler means disposed adjacent the path of the carton to be engaged by an open or displaced flap of a carton, said first pivotal feeler means disposed above the cartons as they move along a conveyor and comprising a first feeler depending from a first pivotal shaft with the lower edge portion of the first feeler disposed adjAcent to and transversely of the cartons as they move along the conveyor, said first feeler also including arms extending downwardly from said feeler adjacent the sides of the cartons as they pass beneath said feeler, second pivotal feeler means disposed beneath the cartons as they move along the conveyor and comprising a second feeler extending upwardly from a second pivotal shaft with the upper edge of the second feeler disposed adjacent to and transversely of the cartons, said conveyor exposing the major portion of the bottoms of the cartons for detection of sagging thereof, and signal means operably connected to said first and second feeler means and disposed to be actuated by either feeler means to signal a displaced flap or a sagging bottom of a carton.
 3. The construction of claim 2 and means inter-connecting said pivotal shafts to effect counter-weighting of said lower upstanding plate by said upper depending plate.
 4. In combination with a conveyor, a detector for cartons moving along a conveyor, comprising pivotal feeler means disposed adjacent the path of the cartons to be engaged by an abnormal projection of a carton, said pivotal feeler means disposed beneath the cartons as they move along the conveyor and comprising a feeler extending upwardly from a pivotal shaft with the upper edge of the feeler disposed adjacent to and transversely of the cartons, said conveyor exposing the major portion of the bottoms of the cartons for detection of sagging thereof, and signal means actuated by said feeler to signal sagging of the bottoms of the cartons.
 5. The construction of claim 4 in which said means comprises a drive motor for the conveyor, a control circuit for said motor, a switch in said signal control circuit, and cam means on said pivotal shaft actuating said switch in response to pivotal turning of said shaft by said feeler.
 6. The construction of claim 3, and means interconnecting said pivotal shafts to operate in unison, and said signal means is actuated by pivotal movement of one of said shafts.
 7. The construction of claim 6 in which said signal means comprises a drive motor for the conveyor, a control circuit for said motor, a switch in said control circuit, and cam means on one of said pivotal shafts to actuate said switch in response to pivotal turning of said shafts be either of said feelers.
 8. The construction of claim 6 in which the conveyor comprises a pair of parallel horizontally spaced side rails, a sheave rotatably carried at each end of each side rail with the sheaves at one end mounted upon a transverse drive shaft carried by the side rails, an endless V-belt mounted on the sheaves for each side rail and providing an upper flight in which the belts engage beneath the opposite side edge portions of the cartons being transported thereon leaving the central portions of the cartons exposed and unsupported, and bracket means carried by each side rail and mounting said first and second pivotal shafts.
 9. The construction of claim 8 in which said signal means comprises a drive motor for the conveyor, a control circuit for said motor, a switch in said control circuit, and means on one of said pivotal shafts to actuate said switch and stop said motor in response to pivotal turning of said shaft by either of said feelers. 